Help tooltips

Most FormField implementations (including your own custom ones, if you want) support the concept of a helpful informational tooltip that can be displayed next to the field. It looks like this:

To enable this, you can invoke setHelpText() on the field in question and supply some non-blank value (setting null or an empty string will disable the tooltip and prevent the information icon from appearing).

ShortTextField textField = new ShortTextField("Text:", 12);
textField.setHelpText("Help icons show up whenever a field has help text");
panel.add(textField);

When the user hovers the mouse over the informational icon, the tooltip appears:

To support this in custom form field implementations, you don't actually have to do anything at all, as the code for this is handled by the abstract FormField class and by the FormPanel class (which handles the rendering of the icon).

You can prevent the help icon from showing up in your custom FormField implementation by overriding the hasHelpLabel() method in your implementing class to return false. Let's look at the default implementation of this method in the parent FormField class:

public boolean hasHelpLabel() {
    return helpLabel.getToolTipText() != null && !helpLabel.getToolTipText().isBlank();
}

This default implementation is generally what you want: the help label will automatically show up if your form field has help text, and will hide itself if not. If you're writing a custom FormField implementation that, for whatever reason, never requires a help label, you could override that method like this:

@Override
public boolean hasHelpLabel() {
    return false; // help label will not show up even if help text is set
}